The invention relates to a transmission drive unit having a self-locking device, in particular for adjusting movable parts in the motor vehicle.
DE 197 53 106 C2 has disclosed a load torque lock which is installed in a drive train and, when the drive is at a standstill, automatically locks the torques which are introduced by the output means. In contrast, the torques which are introduced from the drive side are transmitted in both rotational directions. To this end, a drive shaft is penetrated by the attachment components of an output shaft. Between these two shafts which can be rotated counter to one another, radial webs and clamping and locking elements are arranged which permit or lock a rotation with respect to a clamping ring unit as a function of the drive-side or output-side introduction of the torques. A load torque lock of this type comprises a multiplicity of individual parts which are complicated to assemble and require a large amount of installation space. As a result, the transmission drive unit is relatively large and has a heavy configuration, as a result of which a correspondingly powerful electric motor is required for driving.